*Comment from Arnoldemu: I looked at the code to discover why R-Type was like this.
Double buffer is not used, screen is located from &0040. &5800 even has attribute data just like on a real spectrum. &7800 has a copy of the attribute data (maybe double buffered so colours can be changed and then updated quickly). Screen is only updated where necessary. I think the same programmer worked on both the Spectrum and Amstrad version. Ok, start with the Spectrum version, remove some colours because the cpc can only display 4 colours in mode 1 (without using raster tricks), now use 90% Spectrum code and convert graphics at runtime into CPC form colouring them as you do this. The result is R-type. This explains all.. it explains why the colours are bad and why the game is so slow.
'''It is also to notice that the speccy version was itself ported (graphically) from the Atari ST version.'''
Yet the bad part : it came to Amstrad CPC from the AtariST, but stoped a byte at the Speccy before...
==The good Aspects==